Electronic Post Mail Service - Assignment Example

Electronic Post Mail Service Customer Inserts His/Her Name Customer Inserts Grade Course Customer Inserts Tutor’s Name 18th December, 2011 Outline I. Introduction II. Electronic post office service operation III. Jasper Protocol IV. SMTP V. Conclusion Electronic Post Mail Service Introduction Traditional postal services involved a cumbersome procedural practice in the delivery of mails to their destined addresses. Traditional postal service follows long steps and methods for it to reach the addressed location. With the development of the electronic post mail services, the postal service has consequently improved their services in most countries in the world today. The inefficiencies experienced in the traditional mail service have been greatly reduced. Customer satisfaction has also been boosted through the electronic postal services. Evaluating many offices today, they have replaced memos, physical visits to the premises and even phone calls with the electronic mail service. Popularity of the electronic postal services has increased over the years with the development and advancement of the internet. There are several e-mail providers in the world today, including Yahoo and Gmail which has greatly facilitated the transfer of mails electronically from one place to another all over the world. E-Mail is an electronic mail where messages which are written can be delivered through a computer network; internet. The pro’s of using the e-mail service includes: sending messages to many people in one occasion, allows for attachment of files and sending of hyperlinks to websites. With the availability of a computer network such as the internet, messages can be delivered in any part of the world in a few seconds or minutes avoiding the technical problems of other methods of postal services. Electronic Post Office Service Operation An E-mail account is used to access a network and to facilitate sending of messages through a network such as the internet. Through an Internet Service Provider (ISP), one is allowed to access a network using a satellite modem, a cable modem, DSL or a dial-up telephone connection. An Internet Service Provider offers an e-mail address with an ISP identifier such as .com or .net. Secondly, an ISP offers a POP (Post Office Protocol) server which is the name of a person’s incoming mail server. E-mails addressed to a person are received by the Internet Service Provider’s computer. Thirdly, the ISP provides an SMTP (Simple Mail Transfer Protocol) server which is for purposes of outgoing mail server. Here, the e-mail messages sent by one are processed by the Internet Service Provider’s computer. Lastly, the ISP provides a person with a username and a password, the username is normally a part of a person’s name that is used in the e-mail. The Internet Service Provider system is accessed through the use of both the username and the password. The password is normally a secret code to enhance privacy of the messages being sent and received; it is advisable to change passwords frequently (Stroman, Wilson & Wauson 165). Internet Service Providers avails e-mail software which users can comfortably use the applications to facilitate transfer of mails. Programs such as the Microsoft Outlook Express, Microsoft Outlook, Macintosh Mail, Windows Mail and IBM Lotus Notes among many other e-mail programs are commonly used by business. These e-mail programs have several commands including: New Message - for creating a new message, Print - for printing a paper copy, Read – for viewing a message in a different window, Reply, reply to All, Send and Receive, Forward and Attachment – for sending a computer file (Stroman, Wilson & Wauson 166). Attachments can be a disadvantage if they are big hence takes a long time to downloading the attachment by the recipient; especially in cases where the recipients are experiencing slow internet connections. Other problems of attachments are the translation problems – if the recipient does not have similar program version and finally, infected attachments might contain many viruses which spreads throughout the internet. The protocol for sending an attachment can be observed through probing. The sender should ensure that a recipient has the necessary software for downloading the attachment. An e-mail message can be used to provide an explanation to the recipient on the intention of the attachment. It is also possible to use compression software such as the WinZip to reduce the file size and subsequently the time for downloading by the recipient in cases of slower internet connections. Moreover, some formats might change in the recipient’s computer depending on the model of the printer. Formats such as the Microsoft word documents are prone to changes in terms of the layout on both screen and paper. Therefore, it is important to convert such documents to the Portable Document Format (PDF) to ensure that the document is received exactly as it looks assuming that the recipient has an Adobe Reader Program. Adobe Reader facilitates the opening of the PDF files. One should be aware of the file extensions and the programs which are compatible with them. For example doc, rtf, txt is opened by Microsoft Word, pdf by Adobe Acrobat Reader, pps by PowerPoint, and zip opened by WinZip, etc. Some executable file attachments are programs which can install viruses on the computer; these extensions include exe, bin, vbs, com and sys. Other forms of viruses can be found in legit files such as the Microsoft Word macro viruses. It is advisable to download and scan for viruses before opening a file using anti-virus software (Stroman, Wilson & Wauson 173). Hyperlinks can be used in e-mail messages in cases where there is a limit on the size of the attachment. It is possible to post a file attachment in the internet and consequently send a link to a recipient through an e-mail message. Normally, a World Wide Web address included in an e-mail is in the form of a hyperlink enhancing downloads and view by the recipient. Organizing mails is important to avoid congestion in the inbox hence there is need to create folders for easy referencing. Furthermore, most e-mail services provide an address book to enhance the management of contacts (Stroman, Wilson & Wauson 173). Using client or server based systems for e-mail services is an added advantage to the postal services. It consists of a server process which facilitates interaction between the sender and the receiver of the e-mail. It enables client application interaction over a certain network using network protocols such as TCP/IP (in general OSI RM layer 4). The technology used in client-server system applications offer true data communication applications through using network protocols directly rather than the simple filing method I/O. Secondly, client or server systems allows and accommodates a large number of users per server; normally handles between 2000 to 5000 persons per server. Thirdly, server based system facilitates data integrity. This is because the application that accesses the data store is limited to only the server processes hence corruption of data by networks or workstations in the event of erroneous conditions is avoided. Finally, a client or server based system is advantageous due to the extensibility. Most servers have similar features and architecture which are standardized to enable extension of products. In cases of development of a new functionality, it is easier to integrate it in the management, administration and monitoring framework of an existing server system. Payment in the electronic post office service is made through an electronic self addressed stamped envelope, electronic postmarking and digital certificates. A sender pays for the electronic post services in order for them to access or get a link to the addressed recipient. Payments are generally made through electronic payments such as credit cards. Consequently, most electronic post office service providers oversee the printing and enveloping services for their customers. There are software which measure the amount of content in a scale and calculates the cost of postage and printing. Print postages can be accessed from the software and printing can be done by a recipient online. These printing services include printing on the envelopes, print stamps, shipping label etc. in order to obtain a hard copy or a physical mail. Jasper Protocol Jasper protocol is a simulator that provides a large variety of protocols for communication. The simulator offers a wide range of protocols such as Alternating Bit protocol (ABP), User Diagram protocol (UDP), HTTP, SMTP, Internet Protocol (IP), Sliding Window Protocol (SWP), Trivial File Transfer Protocol (TFTP) and Transmission Control Protocol (TCP). Actions in the jasper are selected for the purpose of sending data in form of messages or delivery of a protocol message. In the jasper simulator, simulation is not run in real time but rather a timeout after sending the message is possible. SMTP Considering the Simple Mail Transfer Protocol (SMTP) simulator, the SMTP is used for transferring messages through the e-mail. SMTP functions over a Transmission Control Protocol (TCP) to ensure a reliable data transfer in a client-server model. Transmission Control Protocol (TCP) is a complex protocol which enables transfer of data between a pair of users in either direction. In TCP, users only send a fixed size of messages and there is no identification of the message. Considering that the maximum packet size is the protocol segment, messages are sent through several numbers of fragments. Transfer of data in TCP depends on the prevailing window size of the receiver. Opening a connection requires a message to be sent with the SYN (synchronize) flag and closing a connection is FIN (finish) flag. PSH (push) is used to send urgent messages as protocol parameter. Delivery of data is not immediate to the receiver unless the PSH flag is set. In cases of a full receiving window, new requests will be sent to request a buffer and the buffered data can be sent in the event the receiving window is opened again (“Send octets to peers”). Ordinary data can be accumulated and later be delivered (“Deliver octets to user”). These messages may have a send sequence number, acknowledgement sequence number and current window showing how many octets can be received. Main commands are used in the SMTP protocol and are in the following order: HELO: names the client (the spelling is deliberate) MAIL FROM: names the sender RCPT TO: names a recipient DATA: asks to send message data cMail Message: sends the message datac cQUIT: finishes the mail session (Robin and Turner para 1) Furthermore, SMTP simulation response codes have limited range of support. The following are the response codes and their explanations: 220 server ready – which shows that a connection has been made and the server is ready for user. Secondly, 221 server closing – notifies acceptance of a QUIT command and sets the readiness of closure of the connection. Thirdly, 250 OK – notifies that the command has been accepted by the command. Fourthly, 354 send mails – is a response showing that the DATA command has been accepted by the server and that the server is waiting for a Mail Message. Lastly, 550 Invalid – is a response code showing that the command has been rejected by the server. Both the 550 Invalid and 250 OK response codes are normally one of the several and same responses (Robin and Turner para 2). After using the Transmission Control Protocol (TCP) to connect to the server by the client, the 220 Server ready response is accrued showing that the server is ready. The client names itself in HELO, to which the server normally gives a 250 Server hello to client response. To send mail, the client issues MAIL FROM and normally gets a 250 Sender OK response. Recipients are named in RCPT TO, normally obtaining 250 Recipient OK responses. However the server can reject a sender or recipient with a 550 Sender invalid or 550 Recipient invalid responses. Once all parties have been named, the client sends DATA to begin message transmission; a 354 Send mail response is expected from the server. At this point, the real protocol would send the lines of the message followed by a full stop. In the simulation, a single Mail Message command stands for this. The server will normally give a 250 Message accepted response and further messages can be sent. Finally, the client sends QUIT and the server responds with a 221 Server closing code. At this point the TCP connection is broken (Robin and Turner para 3). The jasper screenshot for SMTP simulation is as shown in the figure 1below: Figure 1 A mail user agent submits an email to a mail server (mail submission agent) using an SMTP on a TCP port. The mail submission agent then subsequently delivers the mail to a mail transfer agent. The mail transfer agent uses the Domain Server Name (DNS) to look up the MX record for the recipient domain. The MX record then returns with a name of the target host or receiver. Once the target has been established and accepted, the email is then handed to the mail delivery agent (MDA). The MDA delivers the message to the storage directly, or forward them using SMTP or other forms including the Local Mail Transfer Protocol (LMTP). After the delivery of the mail to the local mail server, the message or mail is stored. It can only be retrieved an authenticated user or clients. End-user applications are used to retrieve the mails. The Internet Message Access Protocol (IMAP) enables access to the mail and manages the storage of the mails. SMTP is only a delivery protocol, therefore the IMAP and the Post Office Protocol (POP) is used to retrieve messages from the remote server and manage the mail boxes. POP is disadvantageous in cases where the mailboxes are large hence requires a long time for processing. A POP client has to go through an entire UIDL map to fetch and retrieve a message. Conclusion The advantages of SMTP are that it is the easiest and fastest way to transfer messages from one point to another. In cases of failure SMTP keeps trying to send the message over and over. Secondly, SMTP is very popular and is supported on many avenues by most vendors. Thirdly, SMTP is less costly in terms of administration costs and implementation costs. Lastly, it has a simple addressing scheme. However, SMTP has demerits which includes limited usefulness due to its simplicity and lacks certain functionalities which are important. The benefits accrued from the e-post office services are that they are inexpensive and fast. Mails can reach an intended person in a matter of minutes at a low cost compared to the traditional method of physical mailing. It is sent through a soft copy but can also be delivered in hard copy form. Secondly, emails are very reliable because the mails guarantee the message reaches the right person. It is also an advantage in cases of change in location. Auto responders can also be set to notify receipt of the mail. Work Cited Robin, Lain and Turner, Ken. Simple Mail Transfer Protocol Simulator. University of Sterling, 11 February, 2011. Web. 18 December 2011. Stroman, James., Wilson, Kevin., and Wauson, Jennifer. 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